The invention relates to an adapter device for containers, hereinafter called carrier pods, containing at least one flat object in an ultraclean atmosphere, each carrier pod comprising an elongate body able to be sealed by means of a first door associated to a first lock, and designed to be placed facing a second door of an interface device to perform transfer of the flat object to the production equipment.
Collective containers or carrier pods exist housing a series of silicon wafers, each wafer having for example a diameter of 300 mm. These containers are opened at the level of the production equipment by means of an interface device enabling access to the wafers. An interface device of this kind is described in detail in the document EP-A-0 735 573.
The collective silicon wafer handling technology has given rise to interfacing standards of the machines commonly used for production. This system for transport of the silicon wafer and transfer with the production machines nevertheless proves unsuitable for management of test wafers, which are used singly, or in small numbers, and serve the purpose of adjusting the machine settings.
Incorporating a single silicon wafer in a collective pod able to contain up to twenty-five wafers would have significant incidences on the economy of the production system, on account of the fact that individual handling of test wafers represents a large fraction of about 15% to 20% of a production unit turnover.
To overcome this drawback, individual containers would simply have to be used, for example described in the document FR-A-96 04173, or containers containing several wafers, to handle and stock test wafers. The use of different containers does however give rise to the problem of compatibility with the standardized interfacing device.
The object of the invention is to achieve an adapter device enabling the equipment interfacing means for the opening and closing cycle of collective carrier pods to be used for opening and closing of individual carrier pods.
According to the invention, the adapter device is placed on a movable support plate of the base of the interface device to position the carrier pod at a preset height enabling the standard interfacing system with the equipment machines to be used. A side wall of said adapter device comprises a guiding aperture allowing the carrier pod to pass to bring the first door and its lock into alignment with the front support plane of the side wall. Control means are provided to couple the first door with the second door and to unlock the first door when the side wall accosts against the front face of the interface device.
According to a first mode of use. the adapter device is first installed on the plate of the interface device and then receives the carrier pod.
According to a second mode of use, the carrier pod is first installed on the adapter device, the assembly then being positioned on the plate and behaving as a collective carrier pod with respect to the interface device.
According to one feature of the invention, the carrier pod is fitted on a support plate of the adapter device, which comprises positioning means for centering of the pod, securing means to keep the carrier pod stable on the support plate, and means for reading and transmitting information relating to the individual or collective carrier pods.
The adapter device is advantageously placed on a housing device, which can be permanently fixed to the interface device or be mobile so as to be able to adapt to several interface devices.
According to another feature of the invention, the housing device is equipped with a sliding rack movable from a storage position to a protruding position to enable automatic loading of the adapter device on the plate of the interface device. The sliding rack is provided with a raising mechanism to raise the adapter device from the protruding position to a raised position corresponding appreciably to the level of the movable plate of the interface device.
According to another feature of the invention, the side wall of the adapter device is rendered mobile to enable loading via the top of the carrier pod, and moreover operates in conjunction with a guiding device associated to a return spring to perform locking and unlocking of the securing means.
To eliminate problems of contamination induced by the side wall of the interface device when the two doors are withdrawn, the external face of the side wall is covered by a protective plate, which is automatically removed from said face and transferred onto the second door when mechanical linking of the two doors takes place, following the backward movement of the guiding device in the locking direction after the side wall has accosted with the front face of the interface device. The contamination is thus trapped between the wafer and the second door.
According to an alternative embodiment, the external face of the side wall bears an interchangeable multisheet adhesive block, removal of a contaminated sheet being performed each time the adapter device is used to free a new sheet exempt from particle contamination.